How Can I Make a Lighter "Newman's Own" Vinaigrette at Home?

Q: I am desperate to re-create Newman's Own Olive Oil & Vinegar salad dressing with less oil. I buy Newman's regularly, only to pour (and discard!) at least 3/4 cup of oil from the bottle before using it. Newman's light dressings do not have the same appeal; I am looking for a make-at-home solution with the same exact flavor.